arch/x86/include/asm/xen/hypercall.h

   1 /******************************************************************************
   2  * hypercall.h
   3  *
   4  * Linux-specific hypervisor handling.
   5  *
   6  * Copyright (c) 2002-2004, K A Fraser
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version 2
  10  * as published by the Free Software Foundation; or, when distributed
  11  * separately from the Linux kernel or incorporated into other
  12  * software packages, subject to the following license:
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining a copy
  15  * of this source file (the "Software"), to deal in the Software without
  16  * restriction, including without limitation the rights to use, copy, modify,
  17  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  18  * and to permit persons to whom the Software is furnished to do so, subject to
  19  * the following conditions:
  20  *
  21  * The above copyright notice and this permission notice shall be included in
  22  * all copies or substantial portions of the Software.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  27  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  28  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  29  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  30  * IN THE SOFTWARE.
  31  */
  32
  33 #ifndef _ASM_X86_XEN_HYPERCALL_H
  34 #define _ASM_X86_XEN_HYPERCALL_H
  35
  36 #include <linux/kernel.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/errno.h>
  39 #include <linux/string.h>
  40 #include <linux/types.h>
  41
  42 #include <trace/events/xen.h>
  43
  44 #include <asm/page.h>
  45 #include <linux/pgtable.h>
  46 #include <asm/smap.h>
  47 #include <asm/nospec-branch.h>
  48
  49 #include <xen/interface/xen.h>
  50 #include <xen/interface/sched.h>
  51 #include <xen/interface/physdev.h>
  52 #include <xen/interface/platform.h>
  53 #include <xen/interface/xen-mca.h>
  54
  55 struct xen_dm_op_buf;
  56
  57 /*
  58  * The hypercall asms have to meet several constraints:
  59  * - Work on 32- and 64-bit.
  60  *    The two architectures put their arguments in different sets of
  61  *    registers.
  62  *
  63  * - Work around asm syntax quirks
  64  *    It isn't possible to specify one of the rNN registers in a
  65  *    constraint, so we use explicit register variables to get the
  66  *    args into the right place.
  67  *
  68  * - Mark all registers as potentially clobbered
  69  *    Even unused parameters can be clobbered by the hypervisor, so we
  70  *    need to make sure gcc knows it.
  71  *
  72  * - Avoid compiler bugs.
  73  *    This is the tricky part.  Because x86_32 has such a constrained
  74  *    register set, gcc versions below 4.3 have trouble generating
  75  *    code when all the arg registers and memory are trashed by the
  76  *    asm.  There are syntactically simpler ways of achieving the
  77  *    semantics below, but they cause the compiler to crash.
  78  *
  79  *    The only combination I found which works is:
  80  *     - assign the __argX variables first
  81  *     - list all actually used parameters as "+r" (__argX)
  82  *     - clobber the rest
  83  *
  84  * The result certainly isn't pretty, and it really shows up cpp's
  85  * weakness as as macro language.  Sorry.  (But let's just give thanks
  86  * there aren't more than 5 arguments...)
  87  */
  88
  89 extern struct { char _entry[32]; } hypercall_page[];
  90
  91 #define __HYPERCALL             "call hypercall_page+%c[offset]"
  92 #define __HYPERCALL_ENTRY(x)                                            \
  93         [offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
  94
  95 #ifdef CONFIG_X86_32
  96 #define __HYPERCALL_RETREG      "eax"
  97 #define __HYPERCALL_ARG1REG     "ebx"
  98 #define __HYPERCALL_ARG2REG     "ecx"
  99 #define __HYPERCALL_ARG3REG     "edx"
 100 #define __HYPERCALL_ARG4REG     "esi"
 101 #define __HYPERCALL_ARG5REG     "edi"
 102 #else
 103 #define __HYPERCALL_RETREG      "rax"
 104 #define __HYPERCALL_ARG1REG     "rdi"
 105 #define __HYPERCALL_ARG2REG     "rsi"
 106 #define __HYPERCALL_ARG3REG     "rdx"
 107 #define __HYPERCALL_ARG4REG     "r10"
 108 #define __HYPERCALL_ARG5REG     "r8"
 109 #endif
 110
 111 #define __HYPERCALL_DECLS                                               \
 112         register unsigned long __res  asm(__HYPERCALL_RETREG);          \
 113         register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
 114         register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
 115         register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
 116         register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
 117         register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
 118
 119 #define __HYPERCALL_0PARAM      "=r" (__res), ASM_CALL_CONSTRAINT
 120 #define __HYPERCALL_1PARAM      __HYPERCALL_0PARAM, "+r" (__arg1)
 121 #define __HYPERCALL_2PARAM      __HYPERCALL_1PARAM, "+r" (__arg2)
 122 #define __HYPERCALL_3PARAM      __HYPERCALL_2PARAM, "+r" (__arg3)
 123 #define __HYPERCALL_4PARAM      __HYPERCALL_3PARAM, "+r" (__arg4)
 124 #define __HYPERCALL_5PARAM      __HYPERCALL_4PARAM, "+r" (__arg5)
 125
 126 #define __HYPERCALL_0ARG()
 127 #define __HYPERCALL_1ARG(a1)                                            \
 128         __HYPERCALL_0ARG()              __arg1 = (unsigned long)(a1);
 129 #define __HYPERCALL_2ARG(a1,a2)                                         \
 130         __HYPERCALL_1ARG(a1)            __arg2 = (unsigned long)(a2);
 131 #define __HYPERCALL_3ARG(a1,a2,a3)                                      \
 132         __HYPERCALL_2ARG(a1,a2)         __arg3 = (unsigned long)(a3);
 133 #define __HYPERCALL_4ARG(a1,a2,a3,a4)                                   \
 134         __HYPERCALL_3ARG(a1,a2,a3)      __arg4 = (unsigned long)(a4);
 135 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)                                \
 136         __HYPERCALL_4ARG(a1,a2,a3,a4)   __arg5 = (unsigned long)(a5);
 137
 138 #define __HYPERCALL_CLOBBER5    "memory"
 139 #define __HYPERCALL_CLOBBER4    __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
 140 #define __HYPERCALL_CLOBBER3    __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
 141 #define __HYPERCALL_CLOBBER2    __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
 142 #define __HYPERCALL_CLOBBER1    __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
 143 #define __HYPERCALL_CLOBBER0    __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
 144
 145 #define _hypercall0(type, name)                                         \
 146 ({                                                                      \
 147         __HYPERCALL_DECLS;                                              \
 148         __HYPERCALL_0ARG();                                             \
 149         asm volatile (__HYPERCALL                                       \
 150                       : __HYPERCALL_0PARAM                              \
 151                       : __HYPERCALL_ENTRY(name)                         \
 152                       : __HYPERCALL_CLOBBER0);                          \
 153         (type)__res;                                                    \
 154 })
 155
 156 #define _hypercall1(type, name, a1)                                     \
 157 ({                                                                      \
 158         __HYPERCALL_DECLS;                                              \
 159         __HYPERCALL_1ARG(a1);                                           \
 160         asm volatile (__HYPERCALL                                       \
 161                       : __HYPERCALL_1PARAM                              \
 162                       : __HYPERCALL_ENTRY(name)                         \
 163                       : __HYPERCALL_CLOBBER1);                          \
 164         (type)__res;                                                    \
 165 })
 166
 167 #define _hypercall2(type, name, a1, a2)                                 \
 168 ({                                                                      \
 169         __HYPERCALL_DECLS;                                              \
 170         __HYPERCALL_2ARG(a1, a2);                                       \
 171         asm volatile (__HYPERCALL                                       \
 172                       : __HYPERCALL_2PARAM                              \
 173                       : __HYPERCALL_ENTRY(name)                         \
 174                       : __HYPERCALL_CLOBBER2);                          \
 175         (type)__res;                                                    \
 176 })
 177
 178 #define _hypercall3(type, name, a1, a2, a3)                             \
 179 ({                                                                      \
 180         __HYPERCALL_DECLS;                                              \
 181         __HYPERCALL_3ARG(a1, a2, a3);                                   \
 182         asm volatile (__HYPERCALL                                       \
 183                       : __HYPERCALL_3PARAM                              \
 184                       : __HYPERCALL_ENTRY(name)                         \
 185                       : __HYPERCALL_CLOBBER3);                          \
 186         (type)__res;                                                    \
 187 })
 188
 189 #define _hypercall4(type, name, a1, a2, a3, a4)                         \
 190 ({                                                                      \
 191         __HYPERCALL_DECLS;                                              \
 192         __HYPERCALL_4ARG(a1, a2, a3, a4);                               \
 193         asm volatile (__HYPERCALL                                       \
 194                       : __HYPERCALL_4PARAM                              \
 195                       : __HYPERCALL_ENTRY(name)                         \
 196                       : __HYPERCALL_CLOBBER4);                          \
 197         (type)__res;                                                    \
 198 })
 199
 200 static inline long
 201 xen_single_call(unsigned int call,
 202                 unsigned long a1, unsigned long a2,
 203                 unsigned long a3, unsigned long a4,
 204                 unsigned long a5)
 205 {
 206         __HYPERCALL_DECLS;
 207         __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
 208
 209         if (call >= PAGE_SIZE / sizeof(hypercall_page[0]))
 210                 return -EINVAL;
 211
 212         asm volatile(CALL_NOSPEC
 213                      : __HYPERCALL_5PARAM
 214                      : [thunk_target] "a" (&hypercall_page[call])
 215                      : __HYPERCALL_CLOBBER5);
 216
 217         return (long)__res;
 218 }
 219
 220 static __always_inline void __xen_stac(void)
 221 {
 222         /*
 223          * Suppress objtool seeing the STAC/CLAC and getting confused about it
 224          * calling random code with AC=1.
 225          */
 226         asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
 227                      ASM_STAC ::: "memory", "flags");
 228 }
 229
 230 static __always_inline void __xen_clac(void)
 231 {
 232         asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
 233                      ASM_CLAC ::: "memory", "flags");
 234 }
 235
 236 static inline long
 237 privcmd_call(unsigned int call,
 238              unsigned long a1, unsigned long a2,
 239              unsigned long a3, unsigned long a4,
 240              unsigned long a5)
 241 {
 242         long res;
 243
 244         __xen_stac();
 245         res = xen_single_call(call, a1, a2, a3, a4, a5);
 246         __xen_clac();
 247
 248         return res;
 249 }
 250
 251 static inline int
 252 HYPERVISOR_set_trap_table(struct trap_info *table)
 253 {
 254         return _hypercall1(int, set_trap_table, table);
 255 }
 256
 257 static inline int
 258 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 259                       int *success_count, domid_t domid)
 260 {
 261         return _hypercall4(int, mmu_update, req, count, success_count, domid);
 262 }
 263
 264 static inline int
 265 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 266                      int *success_count, domid_t domid)
 267 {
 268         return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 269 }
 270
 271 static inline int
 272 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 273 {
 274         return _hypercall2(int, set_gdt, frame_list, entries);
 275 }
 276
 277 static inline int
 278 HYPERVISOR_callback_op(int cmd, void *arg)
 279 {
 280         return _hypercall2(int, callback_op, cmd, arg);
 281 }
 282
 283 static inline int
 284 HYPERVISOR_sched_op(int cmd, void *arg)
 285 {
 286         return _hypercall2(int, sched_op, cmd, arg);
 287 }
 288
 289 static inline long
 290 HYPERVISOR_set_timer_op(u64 timeout)
 291 {
 292         unsigned long timeout_hi = (unsigned long)(timeout>>32);
 293         unsigned long timeout_lo = (unsigned long)timeout;
 294         return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 295 }
 296
 297 static inline int
 298 HYPERVISOR_mca(struct xen_mc *mc_op)
 299 {
 300         mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
 301         return _hypercall1(int, mca, mc_op);
 302 }
 303
 304 static inline int
 305 HYPERVISOR_platform_op(struct xen_platform_op *op)
 306 {
 307         op->interface_version = XENPF_INTERFACE_VERSION;
 308         return _hypercall1(int, platform_op, op);
 309 }
 310
 311 static inline int
 312 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 313 {
 314         return _hypercall2(int, set_debugreg, reg, value);
 315 }
 316
 317 static inline unsigned long
 318 HYPERVISOR_get_debugreg(int reg)
 319 {
 320         return _hypercall1(unsigned long, get_debugreg, reg);
 321 }
 322
 323 static inline int
 324 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 325 {
 326         if (sizeof(u64) == sizeof(long))
 327                 return _hypercall2(int, update_descriptor, ma, desc);
 328         return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 329 }
 330
 331 static inline long
 332 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 333 {
 334         return _hypercall2(long, memory_op, cmd, arg);
 335 }
 336
 337 static inline int
 338 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
 339 {
 340         return _hypercall2(int, multicall, call_list, nr_calls);
 341 }
 342
 343 static inline int
 344 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 345                              unsigned long flags)
 346 {
 347         if (sizeof(new_val) == sizeof(long))
 348                 return _hypercall3(int, update_va_mapping, va,
 349                                    new_val.pte, flags);
 350         else
 351                 return _hypercall4(int, update_va_mapping, va,
 352                                    new_val.pte, new_val.pte >> 32, flags);
 353 }
 354
 355 static inline int
 356 HYPERVISOR_event_channel_op(int cmd, void *arg)
 357 {
 358         return _hypercall2(int, event_channel_op, cmd, arg);
 359 }
 360
 361 static inline int
 362 HYPERVISOR_xen_version(int cmd, void *arg)
 363 {
 364         return _hypercall2(int, xen_version, cmd, arg);
 365 }
 366
 367 static inline int
 368 HYPERVISOR_console_io(int cmd, int count, char *str)
 369 {
 370         return _hypercall3(int, console_io, cmd, count, str);
 371 }
 372
 373 static inline int
 374 HYPERVISOR_physdev_op(int cmd, void *arg)
 375 {
 376         return _hypercall2(int, physdev_op, cmd, arg);
 377 }
 378
 379 static inline int
 380 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 381 {
 382         return _hypercall3(int, grant_table_op, cmd, uop, count);
 383 }
 384
 385 static inline int
 386 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 387 {
 388         return _hypercall2(int, vm_assist, cmd, type);
 389 }
 390
 391 static inline int
 392 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 393 {
 394         return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 395 }
 396
 397 #ifdef CONFIG_X86_64
 398 static inline int
 399 HYPERVISOR_set_segment_base(int reg, unsigned long value)
 400 {
 401         return _hypercall2(int, set_segment_base, reg, value);
 402 }
 403 #endif
 404
 405 static inline int
 406 HYPERVISOR_suspend(unsigned long start_info_mfn)
 407 {
 408         struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 409
 410         /*
 411          * For a PV guest the tools require that the start_info mfn be
 412          * present in rdx/edx when the hypercall is made. Per the
 413          * hypercall calling convention this is the third hypercall
 414          * argument, which is start_info_mfn here.
 415          */
 416         return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 417 }
 418
 419 static inline unsigned long __must_check
 420 HYPERVISOR_hvm_op(int op, void *arg)
 421 {
 422        return _hypercall2(unsigned long, hvm_op, op, arg);
 423 }
 424
 425 static inline int
 426 HYPERVISOR_tmem_op(
 427         struct tmem_op *op)
 428 {
 429         return _hypercall1(int, tmem_op, op);
 430 }
 431
 432 static inline int
 433 HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
 434 {
 435         return _hypercall2(int, xenpmu_op, op, arg);
 436 }
 437
 438 static inline int
 439 HYPERVISOR_dm_op(
 440         domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
 441 {
 442         int ret;
 443         __xen_stac();
 444         ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
 445         __xen_clac();
 446         return ret;
 447 }
 448
 449 static inline void
 450 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 451 {
 452         mcl->op = __HYPERVISOR_fpu_taskswitch;
 453         mcl->args[0] = set;
 454
 455         trace_xen_mc_entry(mcl, 1);
 456 }
 457
 458 static inline void
 459 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 460                         pte_t new_val, unsigned long flags)
 461 {
 462         mcl->op = __HYPERVISOR_update_va_mapping;
 463         mcl->args[0] = va;
 464         if (sizeof(new_val) == sizeof(long)) {
 465                 mcl->args[1] = new_val.pte;
 466                 mcl->args[2] = flags;
 467         } else {
 468                 mcl->args[1] = new_val.pte;
 469                 mcl->args[2] = new_val.pte >> 32;
 470                 mcl->args[3] = flags;
 471         }
 472
 473         trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
 474 }
 475
 476 static inline void
 477 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 478                         struct desc_struct desc)
 479 {
 480         mcl->op = __HYPERVISOR_update_descriptor;
 481         if (sizeof(maddr) == sizeof(long)) {
 482                 mcl->args[0] = maddr;
 483                 mcl->args[1] = *(unsigned long *)&desc;
 484         } else {
 485                 u32 *p = (u32 *)&desc;
 486
 487                 mcl->args[0] = maddr;
 488                 mcl->args[1] = maddr >> 32;
 489                 mcl->args[2] = *p++;
 490                 mcl->args[3] = *p;
 491         }
 492
 493         trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
 494 }
 495
 496 static inline void
 497 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 498                  int count, int *success_count, domid_t domid)
 499 {
 500         mcl->op = __HYPERVISOR_mmu_update;
 501         mcl->args[0] = (unsigned long)req;
 502         mcl->args[1] = count;
 503         mcl->args[2] = (unsigned long)success_count;
 504         mcl->args[3] = domid;
 505
 506         trace_xen_mc_entry(mcl, 4);
 507 }
 508
 509 static inline void
 510 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 511                 int *success_count, domid_t domid)
 512 {
 513         mcl->op = __HYPERVISOR_mmuext_op;
 514         mcl->args[0] = (unsigned long)op;
 515         mcl->args[1] = count;
 516         mcl->args[2] = (unsigned long)success_count;
 517         mcl->args[3] = domid;
 518
 519         trace_xen_mc_entry(mcl, 4);
 520 }
 521
 522 static inline void
 523 MULTI_stack_switch(struct multicall_entry *mcl,
 524                    unsigned long ss, unsigned long esp)
 525 {
 526         mcl->op = __HYPERVISOR_stack_switch;
 527         mcl->args[0] = ss;
 528         mcl->args[1] = esp;
 529
 530         trace_xen_mc_entry(mcl, 2);
 531 }
 532
 533 #endif /* _ASM_X86_XEN_HYPERCALL_H */